1992 Force 120HP bogs after sustained speed

[gomar]

I have read a lot of the threads with similar problem but I need help with my 1992 120HP Force. It runs fine except when I cruise at half throttle to WOT for a sustained period (15 minutes or so). It will then begin to run rough and then bog down. When I begin to hear the engine run rough I change to WOT then idle a few times and it seems works its way out of the problem and is ok again. When it is bogging down the fuel line bulb is hard, I have squeezed it and there is no change (I replaced the fuel line and bulb from tank to engine). Choke has no effect. Took it to a dealer and they found nothing. Any help would be greatly appreciated. Thanks

 

[evil^^]

Re: 1992 Force 120HP bogs after sustained speed

Hey, I new at boating and really just started learning about outboard motors. I recently bought a boat. After cleaning the carbs I could go to the lake and run it for about 10 mins okay. After that I would lose power. I check the compression and the 3rd cylinder was like 25. Took the head off and the piston was burnt up. I was told after about 10 min the motor got warm b/c only 2 piston were working. I don't know maybe this will help or maybe not.

Just my 2 cents I'm a newbie to all of this.

Tony

 

[steelespike]

Re: 1992 Force 120HP bogs after sustained speed

Could be a cooling problem.Thermostat,or impeller perhaps.
If impeller is old or you don't knbow when last changed it should be changed anyway.
Are the plugs the right number?You could check the compression.
Should be at least 100 psi and even between cylinders.

 

[capt. stabin]

Re: 1992 Force 120HP bogs after sustained speed

I had the same problem with my 125hp. after i was in full throtel it would bog down I called a force repair shop and said it sounded like a fuel problem. i took it out and seen that when it started to bog down the ball was still hard but when i pumped the ball it stayed runing. the repair man said that it was a fuel pump proble so i checked and found out that i had installed the diaphragh wrong. so you might have a fuel pump problem maybe. oh one more thing what is " WOT" mean?

 

[ski_king]

Re: 1992 Force 120HP bogs after sustained speed

oh one more thing what is " WOT" mean?

WOT = Wide Open Throttle

BTW...My Force 125 has the same issue. It sounds like a fuel problem but haven't been able to track it down (dealing with other problems). One thing to look into is the fuel tank vent. If clogged it will restrict fuel flow.

 

[eedwards]

Re: 1992 Force 120HP bogs after sustained speed

I had the same problem with my 125hp. after i was in full throtel it would bog down I called a force repair shop and said it sounded like a fuel problem. i took it out and seen that when it started to bog down the ball was still hard but when i pumped the ball it stayed runing. the repair man said that it was a fuel pump proble so i checked and found out that i had installed the diaphragh wrong. so you might have a fuel pump problem maybe. oh one more thing what is " WOT" mean?

What did you do wrong maybe thats whats wrong with mine?

 

[capt. stabin]

Re: 1992 Force 120HP bogs after sustained speed

iI put the diaphragm on before the gasket when the gasket goes on first. I guess it needs the extra space to pump back and forth. this will show you the right way to install the parts.
http://www.crowleymarine.com/mercury_parts/1245/50.cfm

 

[eedwards]

Re: 1992 Force 120HP bogs after sustained speed

iI put the diaphragm on before the gasket when the gasket goes on first. I guess it needs the extra space to pump back and forth. this will show you the right way to install the parts.
http://www.crowleymarine.com/mercury_parts/1245/50.cfm

Finally thank you i have tore apart the whole system and nothing has worked
I put it back how i found it and now i know it was wrong in the first place.

 

[gomar]

Re: 1992 Force 120HP bogs after sustained speed

I should have mentioned that I had a new impeller installed this year. And when it is bogging I loosened the gas cap. No change.

 

[eedwards]

Re: 1992 Force 120HP bogs after sustained speed

Gomar did you find out what was wrong?
I redid my gasket and didn't help.
I noticed my ladder sends spray that soaks the one side of my motor and i wonder if this is causing a problem?
I wonder if at WOT it is sucking some water in the carbs.
I did notice tonight after being out my motor was damp when i took off the hood.

 

[gomar]

Re: 1992 Force 120HP bogs after sustained speed

My intermittent bogging problem still remains. I haven't checked compression yet.